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Tytuł:
Structure and Dielectric Properties of V and Y Disorder Doped SrBi2Nb2O9 Ceramics
Autorzy:
Afqir, Mohamed
Elaatmani, Mohamed
Zegzouti, Abdelouahad
Tahiri, Nabiha
Daoud, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/2174596.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
molten salt method
Co-doping
characterization
Opis:
Y and V codoped SrBi2Nb2O9 ceramics, which have been characterized by XRD, FTIR and SEM techniques, were prepared through molten salt using NaCl-KCl medium. Through X-ray diffraction analysis, all prepared samples were matched by undoped SrBi2Nb2O9. The lattice parameters do not depend on the amount of dopants. Under the optimized experimental conditions, the compounds are composed of small crystallites of varying size and orientation, resulting in many micros train defects. FTIR spectra revealed that the dopant promotes a slight decrease in the 612 cm-1 band. A plate-like morphology was revealed by scanning electron microscopy, while Nyquist plots indicate non-Debye relaxation for all compounds. V and Y were incorporated into SrBi2Nb2O9 lattice in order to reduce dielectric loss tangent. Thus, the codoping increases the of SrB1.9Y0.1Nb1.95V0.05O9 (Y0.1V0.05) ceramic whereas, they were significantly decreased in the case of SrB1.8Y0.2Nb2O9 (Y0.2) ceramic. Y0.1V0.05 sample makes up the highest efficient charge transfer, followed by Y0.2 sample representing the lowest.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 4; 1455--1458
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Co Doping on Structural and Optical Properties of NiO Thin Films Prepared By Chemical Spray Pyrolysis Method
Autorzy:
Bakr, N. A.
Salman, S. A.
Shano, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/412102.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
NiO thin films
Co Doping
Chemical Spray Pyrolysis
Optical Properties
Structural Properties
Opis:
In this work, nickel-cobalt oxide (Ni(1-x)CoxO) thin films, where x = 0, 4, 6 and 8 % have been successfully deposited on glass substrates by chemical spray pyrolysis (CSP) technique at substrate temperature of (400 °C) and thickness of about 300 nm. The structural and optical properties of these films have been studied using XRD, AFM, and UV-Visible spectroscopy. The XRD results showed that all films are polycrystalline in nature with cubic structure and preferred orientation along (111) plane. The crystallite size was calculated using Scherrer formula and it is found that the undoped NiO sample has maximum crystallite size (51.16 nm). AFM results showed homogenous and smooth thin films. The absorbance and transmittance spectra have been recorded in the wavelength range of (300-900) nm in order to study the optical properties. The optical energy gap for allowed direct electronic transition was calculated using Tauc equation. It is found that the band gap decreases as the Co-concentration increases and the band gap values were in the range of 3.58-3.66 eV and 3.58 eV for the prepared Nickel-Cobalt Oxide thin films. The Urbach energy increases as the Co-concentration increases and the Urbach. The optical constants including (absorption coefficient, real and imaginary parts of dielectric constant) were also calculated as a function of photon energy. Refractive index and extinction coefficient for Nickel- Cobalt Oxide thin films were estimated as a function of wavelength.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2015, 41; 15-30
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Amelioration of Ultrasonic Transducer to Study CuO Doped Thin Films
Autorzy:
Barakat, M. A. Y.
Powiązania:
https://bibliotekanauki.pl/articles/176534.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasonic
thin films
doping
microstructure
wedge
Opis:
Ultrasonic pulse echo technique was used to study cupric oxide (CuO) thin films. CuO thin films were prepared using sol gel technique. They were doped with Lithium (Li) (1%, 2% and 4%). Thin films’ thickness (d) and band gap energy (Eg) were measured. In addition, elastic moduli (longitudinal (L), shear (G), bulk (K) and Young’s (E)) and Poisson’s ratio (v) were determined to estimate the microstructure properties of the prepared films. The study ameliorated the used transducers to overcome their dead zone and beam scattering; wedges were developed. The results showed the effectiveness of these wedges. They enhanced transducers’ sensitivity by changing the dead zone, beam diameter, beam directivity and waves’ transmission. Also, the study noted that Li doping caused the improvement of CuO thin films to be more useful in solar cell fabrication. Li-CuO thin films had narrower band gap. Thus, they acquired a high quantum yield for the excited carriers; also they gained more efficiency to absorb solar light.
Źródło:
Archives of Acoustics; 2018, 43, 3; 487-495
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complexation of polyaniline with Lewis acids - a Mössbauer spectroscopy study
Autorzy:
Bieńkowski, K.
Oddou, J.
Horner, O.
Kulszewicz-Bajer, I.
Genoud, F.
Suwalski, J.
Pron, A.
Powiązania:
https://bibliotekanauki.pl/articles/148872.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
polyaniline
Lewis acid doping
Mössbauer effect spectroscopy
Opis:
Doping with Lewis acid is a new method for improving solution processibility of conductive polyaniline. We report here detailed Mössbauer spectroscopy studies of polyaniline complexed with Lewis acids containing Mössbauer active nuclei, namely SnCl4 and FeCl3. Films of Lewis acid doped polyaniline cast from nitromethane solutions show stoichiometries of PANI(MeCln)1(CH3NO2)1 (where n = 3 or 4, Me denotes Sn or Fe and PANI denotes one aniline repeat unit), which means that both types of polyaniline nitrogens (imine and amine) participate in the complexation reaction, and one solvent molecule is introduced in the polymer matrix per one Lewis acid molecule. Mössbauer parameters of polyaniline doped with SnCl4 are consistent with hexacoordinated Sn(IV) in an environment of non-equivalent ligands. The spectrum of PANI doped with FeCl3 consists of two doublets with distinctly different Mössbauer parameters, which can be ascribed to two types of complexing sites (amine and imine nitrogens). From the temperature dependence of the isomer shift and the recoil free absorption, we have calculated the Mössbauer lattice temperature, ?m, as probed by both complexing sites, which are 83 K for amine and 126 K for imine sites.
Źródło:
Nukleonika; 2003, 48,suppl.1; 3-7
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-technique characterisation of InAs-on-GaAs wafers with circular defect pattern
Autorzy:
Boguski, Jacek
Wróbel, Jarosław
Złotnik, Sebastian
Budner, Bogusław
Liszewska, Malwina
Kubiszyn, Łukasz
Michałowski, Paweł P.
Ciura, Łukasz
Moszczyński, Paweł
Odrzywolski, Sebastian
Jankiewicz, Bartłomiej
Wróbel, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/2204219.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
wafer homogeneity
wafer defect pattern
surface roughness
indium arsenide
beryllium doping
Opis:
The article presents the results of diameter mapping for circular-symmetric disturbance of homogeneity of epitaxially grown InAs (100) layers on GaAs substrates. The set of acceptors (beryllium) doped InAs epilayers was studied in order to evaluate the impact of Be doping on the 2-inch InAs-on-GaAs wafers quality. During the initial identification of size and shape of the circular pattern, non-destructive optical techniques were used, showing a 100% difference in average roughness between the wafer centre and its outer part. On the other hand, no volumetric (bulk) differences are detectable using Raman spectroscopy and highresolution X-ray diffraction. The correlation between Be doping level and circular defect pattern surface area has been found.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144564
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of residual doping on surface current of InGaAs/InP photodiode passivated with regrown InP
Autorzy:
Braga, Osvaldo M.
Delfino, Cristian A.
Kawabata, Rudy M. S.
Pinto, Luciana D.
Vieira, Gustavo S.
Pires, Mauricio P.
Souza, Patricia L.
Marega, Euclydes
Carlin, John A.
Krishna, Sanjay
Powiązania:
https://bibliotekanauki.pl/articles/2204208.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Tematy:
simulation
residual doping
recombination velocity
surface passivation
regrowth
Opis:
The viability of epitaxial regrowth of non-intentionally doped InP to passivate lateral mesa surfaces of InGaAs photodiodes lattice-matched to InP is investigated, evaluating whether the residual doping of the regrown layer can be responsible for un unexpected increase of the surface current. The effect of residual doping is evaluated via numerical calculations of dark current, considering the range of doping concentrations expected for non-intentionally doped InP. The calculations show that the increase in dark current due to the residual doping of the regrown InP layer is not enough to justify the observed increase in surface current. On the other hand, the technique is still valid as a passivation method if the photodetector pixel is isolated by etching only the top contact layer.
Źródło:
Opto-Electronics Review; 2023, 31, Special Issue; art. no. e144562
1230-3402
Pojawia się w:
Opto-Electronics Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermoelectric properties of bismuth-doped magnesium silicide obtained by the self-propagating high-temperature synthesis
Autorzy:
Bucholc, Bartosz
Kaszyca, Kamil
Śpiewak, Piotr
Mars, Krzysztof
Kruszewski, Mirosław J.
Ciupiński, Łukasz
Kowiorski, Krystian
Zybała, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/2173670.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermoelectric materials
magnesium silicide
bismuth doping
SHS
self-propagating high-temperature synthesis
spark plasma sintering
materiały termoelektryczne
krzemek magnezu
doping bizmutem
samorozwijająca się wysokotemperaturowa synteza
iskrowe spiekanie plazmowe
Opis:
Doping is one of the possible ways to significantly increase the thermoelectric properties of many different materials. It has been confirmed that by introducing bismuth atoms into Mg sites in the Mg2Si compound, it is possible to increase career concentration and intensify the effect of phonon scattering, which results in remarkable enhancement in the figure of merit (ZT) value. Magnesium silicide has gained scientists’ attention due to its nontoxicity, low density, and inexpensiveness. This paper reports on our latest attempt to employ ultrafast self-propagating high-temperature synthesis (SHS) followed by the spark plasma sintering (SPS) as a synthesis process of doped Mg2Si. Materials with varied bismuth doping were fabricated and then thoroughly analyzed with the laser flash method (LFA), X-ray diffraction (XRD), scanning electron microscopy (SEM) with an integrated energy-dispersive spectrometer (EDS). For density measurement, the Archimedes method was used. The electrical conductivity was measured using a standard four-probe method. The Seebeck coefficient was calculated from measured Seebeck voltage in the sample subjected to a temperature gradient. The structural analyses showed the Mg2Si phase as dominant and Bi2Mg3 located at grain boundaries. Bismuth doping enhanced ZT for every dopant concentration. ZT = 0.44 and ZT=0.38 were obtained for 3wt% and 2wt% at 770 K, respectively.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 3; art. no. e141007
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Corrosion properties of Ca-doped TiO2 coatings
Autorzy:
Burnat, B.
Robak, J.
Leniart, A.
Skrzypek, S.
Brycht, M.
Powiązania:
https://bibliotekanauki.pl/articles/283933.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomaterials
surface modification
sol-gel method
doping
corrosion
Opis:
The paper presents the preparation and characterization of TiO2 coating doped with Ca produced by the sol-gel method using titanium alkoxide as the precursor of titania as well as calcium nitrate as dopant source. These coatings were used to modify the biomedical alloy M30NW. Using the optical microscopy and the atomic force microscopy the topography of synthesized coatings was characterized. Whereas using electrochemical methods the corrosion measurements were carried out. Anticorrosion properties of calcium-doped TiO2 coating were determined in PBS solution on the basis of corrosion potential Ecor, polarization resistance Rp, corrosion rate CR, current density in the passive range i0.5 and also breakdown Eb and repassivation Erep potentials. Analogous corrosion tests were also made for the uncoated alloy as well as for alloy coated with pure TiO2 coating. It was stated that modification of M30NW alloy surface by calcium-doped TiO2 coating shows anticorrosion properties in PBS solution. These properties are slightly lower compared to a pure TiO2 coating. The analysis of the topography of TiO2-based coatings showed that calcium doping increases the surface development and roughness of the obtained coatings.
Źródło:
Engineering of Biomaterials; 2014, 17, no. 128-129; 100-102
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania właściwości fizykochemicznych i cytotoksyczności in vitro bioszkieł dotowanych Mg, Sr, Au
Study on physicochemical properties and in vitro cytotoxicity of bioglasses doped with Mg, Sr, Au
Autorzy:
Ciołek, L.
Karaś, J.
Olszyna, A.
Zaczyńska, E.
Czarny, A.
Powiązania:
https://bibliotekanauki.pl/articles/392258.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
biomateriał
bioszkło
domieszkowanie
właściwości fizykochemiczne
aktywność biologiczna
cytotoksyczność
metoda zol-żel
biomaterial
bioglass
doping
physical and chemical properties
biological activity
cytotoxicity
sol-gel method
Opis:
W artykule przedstawiono wyniki badań wytworzonych bioszkieł w układzie CaO-SiO2-P2O5 dotowanych Mg lub Sr, lub Au. W ramach przeprowadzonych badań określono morfologię otrzymanych bioszkieł, a także ich bioaktywność w warunkach in vitro oraz oddziaływanie cytotoksyczne na komórki L929. Ponadto, bioszkło dotowane Au poddano badaniu przy użyciu mikroskopu transmisyjnego z analizą EDS. Stwierdzono, że wytworzone bioszkła in vitro w kontakcie z symulowanym płynem fizjologicznym (SBF) są bioaktywne oraz nie oddziałują cytotoksycznie na komórki L929
This paper presents the results of research on bioglasses in the system CaO-SiO2-P2O5 doped with Mg, Sr and Au. Within the study the morphology of the bioglasses and in vitro bioactivity and cytotoxic effect on L929 cells were determined. Au doped bioglass was examined using transmission electron microscopy with EDS analysis. It was found that the produced bioglasses were bioactive in contact with simulated body fluid (SBF) and were no toxic on L929 cells in vitro tests.
Źródło:
Prace Instytutu Ceramiki i Materiałów Budowlanych; 2014, R. 7, nr 16, 16; 17-28
1899-3230
Pojawia się w:
Prace Instytutu Ceramiki i Materiałów Budowlanych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reversible electron charge transfer in single-wall carbon nanotubes
Autorzy:
Costa, S.
Bachmatiuk, A.
Borowiak-Palen, E.
Powiązania:
https://bibliotekanauki.pl/articles/779706.pdf
Data publikacji:
2008
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
nanorurki węglowe jednościenne
domieszkowanie
Raman
SWCNT
doping
Opis:
Single-wall carbon nanotubes (SWCNT) have proved to be very special materials due to their unique electronic properties. Over the last years many scientists have dedicated their research to the study of the these materials as an electronic system. Amphoteric doping effects (n-type and p-type), which can be reversed, became a very popular way of manipulating the optic and electronic properties of carbon nanotubes. In the particular case of SWCNT, the most common and widely used procedure, which changes their properties, is acid treatment applied as a purification procedure. The effect of the addition of this kind of the dopant has been widely studied but not fully understood so far. Here, we present a study, of two kinds of SWCNT, produced within different techniques: (i) chemical vapors deposition and (ii) laser ablation. The main difference between the two types is the diameter distribution of the obtained materials, which is broad in the first technique and narrow in the second. After the acid treatment it is possible to observe a diameter sensitive doping effect on both samples. Resonance Raman spectroscopy, optical absorption spectroscopy (OAS) in UV/Vis/NIR and the Fourier transform middle-infrared (FTIR) spectroscopy have been applied for the characterization of the samples.
Źródło:
Polish Journal of Chemical Technology; 2008, 10, 2; 1-4
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Knowledge and Attitude in the Field of Doping in Young Athletes of Team Games
Autorzy:
Duda, Henryk
Stuła, Aleksander
Powiązania:
https://bibliotekanauki.pl/articles/2026888.pdf
Data publikacji:
2022-03-31
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
doping
youth
sports games
knowledge
Opis:
Contemporary sport is becoming more and more commercialized, hence the players strive to win at all costs, and to achieve this goal, they consider all means to be allowed. In order to be constantly on top, competitors change their training methods, use various aids, and finally direct their interests towards doping. Doping is considered to be the use of substances and all means intended to artificially increase physical fitness during sports competitions, which may be harmful to the ethics of sport or cause mental and physical harm to athletes. The aim of the research is to assess the knowledge of the problem and attitudes of young people practicing sports games towards the dangers of doping. Assessment of knowledge on the effects of the use of illicit means, and analysis of opinion on the use of doping and strengthening mechanisms for the adoption of pharmacological agents. Research on the knowledge about the use of support measures and doping in sport was carried out among talented youth practicing team sports games in randomly selected clubs of Małopolska, Silesia, Podkarpacie and Opole. Continuation studies were conducted in 2018-2020, they covered 60 girls and 60 boys, aged 16 years. The research was carried out using a questionnaire, the questions of which concerned the following problems: knowledge of the essence of sports doping, the relationship between doping and the principle of fair play in sport, support used in physical recreation, reasons for the use of doping, moral and criminal liability in the use of doping. When analyzing the results of the research, it should be noted that the use of doping in sport is negatively perceived by the examined youth. However, it can be assumed that the knowledge about the support and the problem of doping in sport is insufficient. Setting the main goal - sports success and the related financial rewards, as well as the willingness to be the best in the opinion of the respondents may narrow the boundaries, which may facilitate the decision to use support and doping. These observations seem to be very disturbing, as the analysis of research data concerns young people practicing sports at the stage of education and the utilitarian nature of physical activity.
Źródło:
Central European Journal of Sport Sciences and Medicine; 2022, 37; 57-63
2300-9705
2353-2807
Pojawia się w:
Central European Journal of Sport Sciences and Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ionic conductivity of the CeO2-Gd2O3-SrO system
Przewodnictwo jonowe w układzie CeO2-Gd2O3-SrO
Autorzy:
Dudek, M.
Mosiałek, M.
Mordarski, G.
Socha, R.
Rapacz-Kmita, A.
Powiązania:
https://bibliotekanauki.pl/articles/352955.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
elektrolity stałe tlenku ceru
roztwór stały
stałotlenkowe ogniwo paliwowe
solid oxide electrolytes
ceria-based solid solutions
co-doping
solid oxide fuel cell
Opis:
The Pechini method was used to synthesize nanopowders of CeO2-based solid solutions with the formula Ce0.8-xGd0.2SrxO2- for 0
Jednofazowe proszki roztworów stałych Ce0:8-xGd0:2SrxO2- dla 0
Źródło:
Archives of Metallurgy and Materials; 2011, 56, 4; 1249-1255
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of phase and chemical composition of Bi1-xNdxFeO3 powders derived by pressureless sintering
Badanie składu fazowego oraz chemicznego proszków Bi1-xNdxFeO3 spiekanych swobodnie
Autorzy:
Dzik, J.
Lisińska-Czekaj, A.
Zarycka, A.
Czekaj, D.
Powiązania:
https://bibliotekanauki.pl/articles/353066.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
BiFeO3 ceramics
Nd3+ doping
X-ray phase and structural analysis
ceramika BiFeO3
rentgenowska analiza fazowa i strukturalna
Opis:
In the present paper studies on Bi1-xNdxFeO3 for x =0.1-0.4 are reported. The mixed oxide method followed with pressureless sintering was employed for ceramics fabrication. Thermal behavior of stoichiometric mixtures of simple oxide powders, viz. Bi2O3, Nd2O3 and Fe2O3 was studied by simultaneous thermal analysis. It was found that with an increase in neodymium content the weight loss increased from 0.75% to 3.16% for x =0.1 and x =0.4, respectively. It was found that weight loss took place mainly within two temperature ranges, namely ΔT1 ≈(300-400)0C and ΔT2 ≈(600-800)°C. Bi1-xNdxFeO3 ceramics was studied in terms of its phase composition (X-ray phase analysis) and chemical composition (EDS method) at room temperature. It was found that Bi1-xNdxFeO3 suffered structural phase transition from rhombohedral to orthorhombic symmetry with an increase in neodymium concentration x within the range x =(0.2-0.3).
W niniejszej pracy zaprezentowano wyniki badań ceramiki Bi1-xNdxFeO3 dla x =0,1-0,4. Do wytworzenia ceramiki zastosowano metodę reakcji w fazie stałej z mieszaniny tlenków wyjściowych Bi2O3, Nd2O3 i Fe2O3 spiekanej swobodnie w atmosferze powietrza. Analiza termiczna stechiometrycznej mieszaniny proszków wykazała wzrost ubytku masy proszku przy wzroście zawartości (x) neodymu w mieszaninie (od 0,75% do 3,16% dla x =0,1 i x =0,4 odpowiednio). Stwierdzono, że ubytek masy zachodzi głównie w dwóch zakresach temperatury, a mianowicie ΔT1 ≈ (300-400)°C i ΔT2 ≈ (600-800)°C. Ceramika Bi1-xNdxFeO3 została poddana charakterystyce składu fazowego (rentgenowska analiza fazowa) oraz składu chemicznego (metoda EDS) w temperaturze pokojowej. Stwierdzono, że Bi1-xNdxFeO3 przejawia strukturalną przemianę fazową z fazy romboedrycznej do rombowej przy wzroście koncentracji neodymu w zakresie x =(0.2-0.3).
Źródło:
Archives of Metallurgy and Materials; 2013, 58, 4; 1371-1376
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, structure and dielectric properties of Bi1-xNdxFeO3
Synteza, struktura i właściwości dieletryczne Bi1-xNdxFeO3
Autorzy:
Dzik, J.
Bernard, H.
Osińska, K.
Lisińska-Czekaj, A.
Czekaj, D.
Powiązania:
https://bibliotekanauki.pl/articles/352880.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
BiFeO3
ceramika
impedancja
spektroskopia impedancyjna
Nd3+ doping
ceramics
impedance
spectroscopy
Opis:
In the present study Bi1-xNdxFeO3 (x=0.1-0.4) ceramic powders were synthesized by the conventional mixed oxide method. Stoichiometric mixture of the powders was thermally analysed with Netzsch STA-409 system so parameters of the thermal treatment were determined. Morphology of the ceramic material was observed by scanning electron microscopy, whereas the crystalline structure was studied by X-ray diffraction method. It was found that chemical composition of the ceramic samples corresponds well to the initial stoichiometry of the ceramic powders. An increase in neodymium content caused a decrease in the average size of the ceramic grains. Crystalline structure of Bi1-xNdxFeO3 ceramics for x <0.2 was decribed by rhombohedral symmetry whereas for x >0.3 by orthorhombic symmetry. Dielectric properties were studied within a range of frequency v=20Hz - 1MHz at room temperature by impedance spectroscopy. The Kramers-Kronig data validation test was employed in the present impedance data analysis. Impedance data were fitted to the corresponding equivalent circuit using the CNLS fitting method.
W niniejszej pracy przedstawiono rezultaty badań poświęconych wytwarzaniu i charakterystyce właściwości ceramiki Bi1-xNdxFeO3(x=0.1-0.4). W oparciu o analizę termiczną (DTA) i termograwimetryczną (TG/DTG) dobrano warunki obróbki cieplnej stechiometrycznej mieszaniny tlenków wyjściowych (Bi2O3, Fe2O3 i Nd2O3). Morfologie przełamu wytworzonej ceramiki Bi1-xNdxFeO3 obserwowano przy użyciu skaningowego mikroskopu elektronowego (SEM). Obrazy SEM ceramiki Bi1-xNdxFeO3wykazały, że stężenie neodymu ma znaczący wpływ na rozrost ziarna. Wraz ze wzrostem zawartości neodymu, zmniejsza się wielkość ziarna. Analiza RTG otrzymanej ceramiki Bi1-xNdxFeO3 pozwoliła stwierdzić, że dla x 60,2 układ przyjmuje strukture romboedryczną, natomiast dla x >0,3 strukturę wytworzonego materiału ceramicznego należy opisywać symetrią rombową. Do badania zależności impedancji |Z| i kaąa przesunięcia fazowego w funkcji częstotliwości w zakresie od f = 10 Hz do f = 1 MHz zastosowano sterowany komputerowo miernik impedancji typu QuadTech-1920. Analizę danych eksperymentalnych przeprowadzono metodą CNLS. Dane eksperymentalne otrzymane w wyniku badania ceramiki poddano analizie zgodności danych z wykorzystaniem równan Kramersa-Kroninga.
Źródło:
Archives of Metallurgy and Materials; 2011, 56, 4; 1119-1125
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stabilization Studies of Crystal Structure of Optimally Th-Doped Lead Zirconate Perovskite
Autorzy:
Elsabawy, Khaled M.
El-Hawary, Waheed F.
Powiązania:
https://bibliotekanauki.pl/articles/1191373.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Crystal Structure
Doping
Perovskite
Visualization
XRD
Opis:
The optimally thorium-doped Pb0.9Th0.1ZrO3 was selected for studying thorium doping effect on the structural parameters of lead zirconate crystal. The investigations were made on the low concentrations range of thorium doping 0.0 ≤ x ≤ 0.25 mole. The present investigations are concerned by confirming that thorium dopings play an important role as stabilizing agent inside internal structure of crystal lattice of Pb1-xThxZrO3 where x = 0.1 mole. XRD-measurements indicated that Thorium dopant substitutes successfully on the A-sites of lead zirconate without damaging the main crystal structure at x = 0.1 mole. Visualization and theoretical investigations were concerned by matching and comparison of bond distances ,torsions on angles of investigated compound to clarify success of thorium doping on the perovskite structure.
Źródło:
World Scientific News; 2016, 33; 56-66
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
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